Philo Sofee wrote: ↑Mon Jul 11, 2022 12:29 pm
So scientists propose a multiverse (there goes Occam's Razor with a vengeance!)
Like any version of the principle of parsimony, Occam’s razor is a rough heuristic that can’t really be consistently applied. Appealing to such an idea is usually a last resort.
Philo Sofee wrote:…and then if someone else doesn't believe it, it is up to THEM to explain why and THEY must defend their reasons?!? B.S.. I am not obligated to believe something simply because someone proposes it, even if it is proposed with logic.
But that isn’t what he is doing:
Sean Carroll wrote:0:43:46.1 SC: So that’s three different versions of physics-oriented multiverse. The cosmological multiverse, the many worlds of quantum mechanics, and an eternal fluctuating cosmology. The eternal fluctuating cosmology is a kind of a multiverse in time. It’s not like different regions of space or are different universes, but if you wait long enough, whatever kind of universe you want to think about will fluctuate into existence. So it is effectively a multiverse.
0:44:11.6 SC: One thing to emphasize, which I’ve noted all along, is that every single one of these three options is a consequence of other ideas. It is not put forward for its own sake. And it’s a consequence of other ideas that were proposed in order to account for data. In order to explain the universe that we see… So it is 100% the standard scientific process going on here. There is no sense, some diversion or distraction away from doing real science by thinking about these different multi-verses.
I don’t understand why you think he is talking fantasy when he devotes two hours trying to walk people through his thinking.
Philo Sofee wrote:Wolfgang Smith is right, science has become a dogmatic affair and has lost it's way. It is NOT science to say, "Hey we have a proposal, without any kind of evidence whatsoever, so it is utterly pure fantasy, but you have to believe us, or else say why you don't accept our fantasy." The plain fact is, I do not have to believe one word of your fantasy, and I truly have no obligation whatever to justify me simply saying no to it.
The only thing you are really voicing here is an objection about dialectical procedure, but you still need some kind of epistemic justification as to why you think there isn’t an entailment between prevailing theories and some version of a multiverse.
I do have to say Carroll is spot on with this:
Sean Carroll wrote:0:45:39.4 SC: The all too easy objection to the multiverse is that it’s not falsifiable. Famously Sir Karl Popper, a philosopher of science proposed the falsifiability criterion to demarcate scientific theories from non-scientific theories. Now, almost none of the physicists who bring up falsifiability have actually read when Karl Popper wrote, but they carry on their shoulder a little straw Popper that they have simplified down to this motto that says, “If you can’t falsify the theory through an experiment then it’s not science.” That’s not what Popper said. That’s certainly not what philosophers of science believe. They don’t even believe the falsifiability works at all, generally… Most of them… As a demarcation between science and non-science.
I’ve read every technical publication of Popper’s and most of his non-technical work and I will completely co-sign the above. He goes on to say:
Sean Carroll wrote:0:48:05.2 SC: So it’s saying something definite, but you don’t know. You’re not gonna be able to test it in any simple way. So should we count it as science? Well, of course, we should. And Popper, I think would agree with me about this ’cause he had different fish to fry. The basic issue is that these scenarios could be true, and that really could be the way nature works. And that’s a difference with what Popper was worried about. There really could be other universes out there elsewhere in the wave function or in space or in time.
0:48:36.5 SC: And the reason why it matters is because whether or not there are these other universes affects how we do science here in this universe trying to explain the data that we have in our observable part of the universe. When you do cosmology or when you do these large scale scenarios to explain the universe, things are connected to each other. They’re interrelated. We talk about the multiverse and things we can’t observe. But the reason why we talk about them is because they play an explanatory role in what we do observe. And this is just science. This is not anything new.
Carroll either consulted an excellent source on Popper or did a lot of legwork reading him, because I can only agree. More to the point, the bolded part is a routine practice. I can understand why someone might dispute that a multiverse is somehow entailed by current data and explanatory models, but I don’t understand this sentiment:
Philo Sofee wrote:Carroll cannot possibly be taken seriously that he is working with 100% science, in the multiverse, when there is precisely, and exactly NO EVIDENCE for this postulate, in any manner, nor, in theory can there be.
So now I’m curious Philo, could you walk me through the following quote and tell me why it can’ be considered science?
Sean Carroll wrote:0:49:14.0 SC: I’m not in the camp that says, we need to think about a new paradigm for doing science because of the multiverse. It’s exactly the same paradigm we always had. We come up with a theory, we use it to account for the data. So for example, in the cosmological multiverse, we invoke the cosmological multiverse as an explanation for the observed value of the vacuum energy and possibly for the observed values of other constants of nature, like the mass of the Higgs boson and so forth. To account for the apparent mysterious numbers that we observe in physics. The fine tuning of certain parameters. That was what Steven Weinberg tried to do before we even knew the cosmological constant was not zero. And so the point is, if you are a working physicist and you say, I would like to understand why the vacuum energy has the value it does. Whether or not you think that the cosmological multiverse is a promising theory… Absolutely, indisputably affects what kind of theoretical ideas you will consider and put forward.
0:50:20.7 SC: If you don’t think that the multiverse makes sense or is there, then it is beholden on you to come up with some dynamical mechanism that explains why the cosmological constant has the value we observe. If you do think that the multi-verse is there, then arguably, you don’t need to do that, it’s just an environmental selection effect. Although you can’t have a dynamical theory that predicts with probability, one, that the cosmological constant has a certain value and think that that’s a good theory if it has other values elsewhere.
Carroll is just making an inference to the best explanation. How does favoring an interpretation of data and asking for a more viable alternative to that interpretation somehow not scientific?